Spline arbor chuck



June 5, 1951 A KMANN 2,555, 6

IN V EN TOR. Grthur Mackmann A. MACKMANN SPLINE ARBOR CHUCK June 5, 1951 10 Sheets-Sheet 2 Filed March 17, 1947 INVENTOR. anthw 772ac/rmann O MM June 5, 1951 A. MACKMANN SPLINE ARBOR cuucx 10 Sheets-Sheet 3 Filed March 17, 1947 IN VEN TORI. CZrf/Zw Mackmwm v a l\ June 5, 1951 A. MACKMANN 2, 6

SPLINE ARBOR cnucx Filed March 17, 1947 i0 Sheets-Sheet 4 aa/4 2 2 as d 2.06 5/0 44 I? m INVENTOR. .519. 12 arlfiur filaakflza zn BY I 1 June 5, 1951 A. MACKMANN 2,555,496

PLINE ARBOR CHUCK 1O Sheets-Sheet 5 Filed March 17, 1947 IN VEN TOR. art/2w" mac/cmann 'V QQAZZM 10 Sheets-Sheet 7 INVENTOR. Clrihw" mackmann June 5, 1951 A. MACKMANN SPLINE ARBOR CHUCK Filed March 17, 1947 June 5, 1951 V A. MACKMANN 5,496

SPLINE ARBOR CHUCK Filed March 1'7, 194"! 1O Sheets-Sheet 8 INVENTOR. a flzur madam June 5, 1951 A. MACKMANN 2,555,496

SPLINE ARBOR CHUCK Filed March 17, 1947 10 Sheets-Sheet 9 JNVENTOR. art/2w" mac/(mam 548 344 atty,

June 5, 1951 A. MACKMANN 2,555,496

SPLINE ARBOR CHUCK Filed March 17, 1947 10 Sheets-Sheet 1o F. 38 786 IN VEN TOR.

7 drthur mackmann 5 f? BY 7 r j ,fl Z

Patented June 5, 1951 UNITED STATES PATENT OFFICE This invention relates to spline arbor chucks.

It is an object of my invention to provide an internal or external spline arbor chuck employing special and simple cam locking means for holding a workpiece with respectively internal or external spline teeth.

Another object is to provide a spline chuck having fixed and movable spline elements with means positively limiting the adjustment of the movable element.

An additional object is to provide a spline chuck with a single adjusting and locking element capable, in a single stroke, of movement selectively to looking or fully retracted position.

It is also an object of my invention to provide a spline chuck for a hollow workpiece with means for positively centeringthe workpiece for concentric machining.

An additional object is to provide a statically balanced adjustable spline chuck for accommodating a workpiece to be treated so as to have static and dynamic balance.

It is another object to provide spline chucks with locking means operable manually, hydraulically or pneumatically.

Further objects and advantages of the invention will appear as the description proceeds.

The invention will be better understood upon reference to the following description and accompanying drawings, in which:

Fig. 1 is a view, partly in section and partly in elevation, of an external directly-actuated manual spline chuck constructed in accordance with one form of my invention.

Figs. 2, 3 and 4 are views taken as indicated by the lines 2--2, 3-3 and 4-4, respectively, in Fig. 1.

Fig. 5 is a view, partly in section and partly in elevation, of a modified external directly-actuated manual spline chuck.

Figs. 6 and '7 are sectional views taken as indicated by the lines 66 and 7-7, respectively, in Fig. 5.

Fig. 8 is an elevational view of a still further modified form of external directly-actuated manual spline chuck.

Figs. 9 and 10 are views taken as indicated by the lines 9-4! and lill9, respectively, in Fig. 8.

Fig. 11 is an enlarged fragmentary sectional view taken as indicated by the line H-ll in Fig. 9.

Fig. 12 is a sectional view taken as indicated by the line l2l2 in Fig. 11 but with the adjustable spline ring shifted into clamping engagement with the workpiece.

Fig. 13 shows an internal directly-actuated manual spline chuck.

Figs. 14 and 15 are sectional views taken as indicated by the lines I l-l4 and 15-45, respectively, in Fig. 13.

Fig. 16 is a sectional view taken as indicated by the line l6l ii in Fig. 13, but with the adjust able spline ring shifted to clamp the workpiece.

Fig. 17 is a view, partly in section and partly in elevation, of a modified internal directly-actu ated manual spline chuck.

Figs. 18 and 19 are sectional views taken as indicated by the lines l8l8 and l9ll9, respectively, in Fig. 1'?

Fig. 20 shows an external semi-indirectly actuated manual spline chuck constructed so as to be in static balance.

Fig. 21 is a sectional view taken as indicated by the line 2 [-21 in Fig. 20.

Fig. 22 is a sectional view similar to Fig. 21 but with the adjustable spline ring shifted to clamp a workpiece.

Fig. 23 is a sectional view taken as indicated by the line 2323 in Fig. 20.

Fig. 24 is a plan view of a modified external semi-indirectly actuated manual spline chuck.

Figs. 25 and 26 are views taken as indicated by the lines 25-Z5and 26*26, respectively, in Fig. 24.

Fig. 27 is a sectional view taken as indicated by the line 2121 in Fig. 26.

Fig. 28 is a sectional view taken as indicated by the line 28-28 in Fig. 25.

Fig. 29 is a sectional view taken as indicated by the line 29-29 in Fig. 26.

Fig. 30 is a fragmentary view, partly in section and partly in elevation, of a still further modified form of indirectly actuated spline chuck.

Figs. 31 and 32 are sectional views taken as indicated by the lines 3l-3l and 3232, respectively, in Fig. 30.

Fig. 33 is a fragmentary sectional view of an external spline chuck somewhat similar to those shown in Figs. 24. to 32 but operable by pneumatic or hydraulic means, and taken as indicated by the line 33-33 in Fig. 34.

Fig. 34 is an end elevational view taken as indicated by the line 34-34 in Fig. 33.

Figs. 35, 36, 3'7 and 38 are sectional views taken as indicated respectively by the lines 35-45, 3E 3E. 31-31 and 38-48 in Fi 33.

Referring now to the drawings, wherein several embodiments of the invention are illustrated, and more particularly to the form appearing in Figs. 1 to 4, there is shown a back face plate 50 which may be altered to suit various installations and has a series of holes 5| whereby the same may be bolted as at 52 to a rotating part 53 of a lathe or other suitable machine tool. Integral with the plate 59 is an inner spline ring 55 having external spline teeth 55 and a reduced cylindrical central boss 56 extending outwardly therefrom and forming an internal bearing for an adjustable middle spline ring 5'! having external spline teeth 58 adjustable into and out of register with the teeth 55, as will appear. An outer spline ring 59 is secured as by screws 65 to the boss 56 and has external spline teeth 6! at all times in register with the teeth 55, the middle spline ring 51 being in sliding face engagement with the relatively fixed inner and outer spline rings 54 and 59. All of the spline teeth are identical in pitch diameter, number and profile. The middle spline ring 5'! has a slot 62 open at the inner periphery 53 of said ring and having parallel sides 64 and 55. A cylindrical cam rod 55 is disposed in all of the spline rings 55, 51 and 59 and has a flange Bl seated in a depression 68 of the outer ring 59 and engaging with the adjacent face it of the middle ring 51 so that said rod is capable of rotary movement only, The rod 66 has a preferably polygonal free extension H for the reception of a socket wrench (not shown), or may be formed with or securely receive a lever (not shown) for rotating the rod. The part 72 of the cam rod 66 within the middle spline ring 57 is cut identically away at opposite quadrants, providing curved surfaces 13, Hi starting at the periphery of the cylinder as shown at 15, I6 and terminating slightly radially inward of said periphery as shown at 71, 18, the quadrant at the minimum radial portions 'of said curved surfaces being identically cut away to provide adjacent tangential fiat surfaces 19, 80 substantially 90 to each other. The curved cam surfaces '53, M are disposed for engagement with the two parallel sides 54, 55, respectively, of the slot 52 in the middle spline ring 51 and are so formed that the diametrical distance between all parts of said curved cam surfaces, through, the axis 82 of the cam rod 56, is

uniform and simultaneously slidably engageable with the respective sides of said slot, each cam surface, however, beingof gradually increased radius from the flat surface 59, as continguous thereto to the other end l5, E5 of said curved surface, as above noted.

7 When the cam rod 66 is in the relative position shown in full lines, with the flat surface 9 engaged with the side 5 of the slot 52, all of the teeth 55, 58 and BI of the spline rings 54, 5 and 59, respectively, are in perfect register, as best seen in Fig. 4, so that the internal teeth 84 of a workpiece 86 to be machined may be readily slipped into splined relation to all of the spline teeth. Now if the cam rod 55 is rotated in the direction shown by the arrows 88, the adjustable spline ring 5'! will be adjusted clockwise, as shown by the arrows 96, by reason of the engagement,

with the right side 54 of the slot 62, of points on the cam surface 13 of progressively increasing radius (the other side 65 of the slot being at the same time engaged with points on the other cam surface 14 of progressively reduced radius). The parts are preferably dimensioned to allow for a maximum shift of .020" at the periphery of the spline rings, although this amount may be increased or decreased, as desired. The maximum shift of the middle spline ring 51 can of course occur when the cam rod 55 has been rotated 90, whereupon the fiat surface 86 will be in full s it-- face engagement with the left side 55 of the slot 62, and the radially outermost or high end 15 of the cam surface '53 will be engaged with the right side 64 of the slot. When, with the rod 55 at the limit just described, the rod is rotated counterclockwise, it can be turned only whereupon the flat surface it will'engage the right side 65 of the slot 52, and then the teeth 58 of the middle spline ring 5? are in register with the teeth 55 and 5! of the relatively fixed spline rings 55 and 59, respectively.

Assuming now that the teeth 55, 58 and SI of all of the spline rings 55, El and 59, respectively, are in, perfect register and the internal spline teeth 85 of the workpiece 55 are in splined relation thereto, as best shown in full lines in Fig. l, the workpiece teeth may be rigidly clamped by the spline rings pursuant to rotation of the cam rod 56 clockwise, i. e., in the direction of the arrows 88 (Figs. 1, 2 and 4) to the extent necessary to take up the slack or tolerance 92 between the workpiece teeth and the spline ring teeth, the cam surface "E3 of the cam rod 55 becoming wedged against the side of the slot t2, so that the rod will remain securely in any position to which it is adjusted. When the rod 65 is rotated counter-clockwise, the other cam surface Ml, acting upon the left side 65 of the slot 62, cams said side to the left and thus shifts the middle spline ring 5? counter-clockwise to release the workpiece, in the same manner that the other curved cam surface 73 moved the right side 54 of the slot to the right as described above.

If desired, buttons or dowels 95, mounted in the outer spline ring 55, may serve as means against which the workpiece 85 may abut for positioning its internal teeth 8 in proper splined relation to the teeth 55, 55 and 6! of the three spline rings 55, 57 and 55, respectively. Each internal tooth S4 of the workpiece 36 is thus clamped at the end portions 35 thereof at one side and at the intermediate portion 95 thereof at the other side. 7

Figs. 5, 6 and '7 show an adaptation of my invention to a spline arbor lilil having an end cen-' tering recess I52 for positioning in a lathe. The arbor I 953 may have a flange lt i against which an. abutment or workpiece-positioning collar 05 may be placed for engagement byan end m5 of an impeller or other workpiece Hi3 having internal spline teeth I I 2. The collar 65 is disposed about a cylindrical shaft section 1 33 having axially spaced series of identical registered spline teeth I M and H6 which for convenience may be referred to as fixed spline rings H8 and 523', leaving an intervening annular space E22 in which an adjustable middle spline ring are, having spline teeth H26, is accommodated, the middle spline ring being formed of two, mating semi-cylindrical parts I28 and H59, adapted to be separately fitted in the space I22 and then secured together. as by screws i152 having preferably wrench socket heads and threaded into tapped holes E35. in one of the mating parts.

The fixed spline rings MB and 520 are formed with registering bores use and M2 for journaling a cylindrical cam rod 555, said rod having an an nular groove I55 in which a pin [43, driven in a the middle spline ring E24 substantially like the corresponding structure described above.

Figs. 8 to 12 show another modification of my invention, particularly suited tor workpieces to be subjected to heavy machining operations. In thi form, an arbor 255, having centering end recesses 222 for mounting on a lathe, has fixed axially spaced external spline rings 2M and 253 with their respective teeth 258 and 2H) identical and in register, and an intervening annular space or groove 2l2 for the reception of an adjustable middle spline ring 2 ill having teeth 2 36 identical with the aforesaid teeth. The arbor 252 is formed with a longitudinal bore 2 I8 parallel to its axis and so located that, in the reduced arbor shaft section 225 defining the bottom of the annular space M2, the major portion of said bore, considered cross-sectionally, is formed as a part-cylindrical groove 222. The arbor 250 has a preferably reduced bore 224 coaxial with the bore 2 l5.

A cam rod 22% has cylindrical portions 228 and 225 disposed in the bores H8 and 224, respectively, with an intermediate cut-away locking cam portion 23s seated in and projecting radially from the groove 222 and into a 99 V- groove 232 with flat sides 23 235 formed at the inner periphery 233 of the middle spline ring 2M. Adjacent quadrants of the cam portion 230 are cut away symmetrically to provide curved cam surfaces 225 and 242 of progressively re duced radius from the juncture 234 of said quadrants, and parallel flat surfaces 245 and 248 extending tangentially from the minimum radial portions of said curved surfaces and terminating at the cylindrical surface of the rod. The flat surface 228 is in flatwise engagement with the side 234 of the V-groove 232 (as shown in Fig. when the middle ring 2M is in neutral position (Fig. 8), i. e., when the teeth 2H5 of said ring are in register with the fixed arbor teeth 2% and 212, enabling the internal teeth 25!) of a workpiece 252 to be placed in splined relation thereto. The free end 254 of the cam rod 223 has a wrench socket 258. In order to lock the workpiece 252 to the arbor 258, the operator applies a wrench to the socket 258 and rotate the rod 228 in the direction of the arrow 2%, thereby causing portions of progressively increasing radius on the curved cam surface 241] to slide relative to the side 2% of the V-groove 232 and thus shift the middle spline ring in a clockwise direction (Fig. 10) so that each internal tooth 2553 of the workpiece 252 is clamped vise-like at the end portions 232 at one side by the "red spline ring teeth 2%, 2H2 and at the intermediate portion 254 at the other side by the middle spline ring teeth 215, the engagement between the cam surface and the groove side being wedge like to insure against accidental disturbance. The ultimate limit of such movement is reached, in the absence of a workpiece, when the flat tangential surface 228 is in flatwise engagement with the V-groove side 236. The V-groove side 235 during such movement is unobstructed because it engages portions of the cam surface 232 of progressively reduced radius. When it is desired to release the workpiece, the operator applies a wrench to the socket and turns the cam rod 226 counterclockwise, causing portions of progressively in creased radius of the cam surface 242 to slide against the surface 235 of the V-groove 232 and thereby rotating the middle spline ring 2 Hi countor-clockwise until the flat tangential surface 24!; comes into fiatwise engagement with the V-groove side 234, when the several spline teeth are again in register. The V-groove side 234 during this latter movement is unobstructed because it engages portions of the cam surface 243 of progressively reduced radius.

The middle spline ring 2M is formed of two semi-cylindrical part 215 and 212 which are fitted in the annular space H2 and secured together as a complete ring as by screws 214 threaded into tapped holes 216 in one of the parts and having wrench socket heads seated in the other part.

The reduced portion 229 of the cam rod 225 has an external annular groove 23% in which is disposed a pin 282 driven in a hole 284 in the fixed spline ring 204 for confining the rod to rotary motion.

The V-groove 232 is of relatively small depth due to the location of the major portion of the rod 226 in the shaft portion 229, 50 that the middle spline ring 2I4, outwardly of the V- groove, is of substantial thickness and hence of sufficient strength to withstand the stresses resulting from heavy machining operations on the workpiece 252.

Figs. 13 to 16 show a form of internal spline chuck 294 made in accordance with my invention. This form may include a backing plate 296 to which the flange 298 of a spline chuck body 309 is connected as by screws 352: which may also be employed to mount the backing plate and body on a suitable rotating member 304 of a lathe or other suitable machine tool. The body 300 has a sleeve 306 which is formed with an internal spline ring 308 having teeth 3H3, and is counterbored at 3l2 for the reception of an adjustable middle internal spline ring 3M having teeth 3|6 identical with the aforesaid teeth. The sleeve 306 is further counterbored at 33s for the reception of an outer internal spline ring 332 having teeth 334 identical with the aforesaid teeth and formed externally with a keyway 335 in which a pin or dowel key 338 projects from the sleeve 305, whereby said spline ring is held against rotation. Beyond the outer face 339 of the spline ring 332, the sleeve 356 is formed with an inner annular groove 3 38 in which a split snap retainer spring ring 342 is slipped, whereby the spline rings 3M and 332 are retained in assembly with the body 328.

The middle spline ring 354 has a slot 350 parallel to its axis and interrupting it outer periphery 352 and having parallel sides 35 and 355. The portion of the sleeve 3% adjacent the inner side 35! of the middle spline ring 3M has a bore 358 in which the cylindrical portion 362 of a cam rod 352 is rotatably received, said rod having a reduced cam extension 35 which fits in the slot 351! and cooperates with the sides 354 and 356 thereof, as will appear. The backing plate 295, adjacent the body 359, has a counterbore 366 coaxial with the rod portion 365 coaxial with the rod portion 362 and a coaxial bore 368 of reduced diameter for admitting corresponding portions 310 and 312 of the rod 352. The rod portion 3T2 extends free of the backing plate 300, and receives a handle 32 i securely held thereon by a pin 315 and jam nuts 3'58 applied to the threaded end 385 of the rod 352, a washer 382 surrounding said rod portion between the backing plate and the handle.

The cam portion 364 of the cam rod 352 is symmetrically cut away at diametrically opposite quadrants to provide curved cam surfaces 390 and 392 of progressively reduced radius from the normal cylindrical surface of the rod and tangential fiat surfaces 400 and 402 extending from the portions of minimum radius to the adjacent cylindrical surface. The distance between said cam surfaces 390 and 392, through the axis of the cam rod 332, is uniform for all portions of the respective cam surfaces, and is exceeded by the width of the slot 353 only to the extent enabling said surfaces to have sliding contact with the sides 354 and 356 of the slot during rotation of the cam rod. When the parts are arranged with the flat surface 400 in fiatwise engagement with the side 354 of the slot 353, as shown, the internal teeth 3! 0, 3| 6 and 334 of all of the spline rings 308, 3|4 and 332 are in register, so that the external spline teeth 406 of a workpiece 438 may be readily slipped into splined relation to all of the internal teeth. To look the workpiece 488 in the spline chuck, the operator rotates the handle 3'! in the direction indicated by the arrows M0, with the result that portions of the locking cam surface 390 of progressively increasing diameter engage the side '354 of the slot 350, thereby shifting the middle spline ring 3M in the direction indicated by the arrow 4H (Fig. 14) until each tooth 3l6 of the middle spline ring grips the intermediate portion M2 of an external tooth 403 of the workpiece 438 at one side while a tooth 3), 334 of each of the relatively fixed internal spline rings 308,332 grips end portions 4M of said external tooth at the opposite side with a vise-like pressure, the locking cam surface 390, as said pressure is increased, being forcibly wedged against the adjacent side 354 of the slot 35!] to provide in effect a positive lock which will not be accidentally disturbed. r

In no event can the rod 362 be so turned beyond the position at which the flat surface 402 engages the side 356 of the slot 350. To release the workpiece 4138, the operator rotates the handle 374 in the opposite direction, whereupon the cam. sur face 392 of the rod 362 earns the Wall 355 of the slot 359 to turn the middle spline ring 3| 4 in the direction of the arrow 4|6 (Fig. 14) until the flat surface 4-98 again comees into flatwise engagement with the side 354 of the slot, thus re-registering the spline teeth 3H5 of the middle ring 3M with the spline teeth 313, 334 of the fixed rings 398, 332. Adjustment of the middle spline ring in either direction is unobstructed by virtue of the fact that in each case the inact-ive curved cam surface recedes from the inactive wall of the slot 350 by the amount by which the active curved cam surface advances the active wall of the slot.

Figs. 17, 18 and 19 show another form of internal spline chuck, indicated generally at 423. It may comprise a plate-like body 422 assembled with an inner internal spline ring 424 having teeth 426 and having a sleeve 428 in which is disposed an adjustable middle spline ring 430 having internal teeth 432 identical with the afore- 'said teeth. An outer internal spline ring 434,

having teeth 435 identical with the aforesaid teeth 42% and 432, is engaged with the free end 438 of the sleeve 428 and projects somewhat in said sleeve adjacent the middle spline ring 436, the plate 422 and inner and outer spline rings 424 and 434 being secured together by bolts 443 and confining the middle spline ring 430 to rotary movement, caused by means presently to be described.

.The middle spline ring 430 has an external longitudinal slot 442 interrupting the outer periphery 444 of said ring, said slot having parallel sides 446 and 448. The inner and outer spline rings 424 and 434 have bores 450 and 45] which are co-axial with a bore 452 and counterbore 454 in the backing plate 422, the various bores being co-axial and alined with the middle ring slot 442. A cam rod 456 is dimensioned to correspond with the various bores 45B, 452 and 454 and fitted thereinto, said rod having an enlargement 458 confining said rod to rotary motion, the outer end 433 of said rod being disposed at the free face 462 of the backing plate 422 and being formed with a wrench socket 464. The portion 466 of the cam rod 456 disposed in the. middle ring slot 442 is symmetrically cut away to provide curved cam surfaces 463 and H0 in diametrically opposite quadrants, each such surface being of progressively reduced radius from the normal cylindrical surface of the rod, and to provide, in the quadrant adjacent the minimum radius ends of said surfaces, fiat surfaces 472 and 414 extending tangentially from said ends and terminating in the normal cylindrical surface 473 of the rod portion 455, the distance between said curved cam surfaces for all portions thereof through the axis 4730f the rod being uniform and said curved surfaces having simultaneoussliding engagement with the respective walls 446 and 443 of said slot. As will be understood from various explanations above, rotation of the cam rod 456 in a clockwise direction as indicated by the arrow 43% in Fig. 18 will have the effect of turning the middle spline ring 435! in the direction of the arrow 482 sufficiently to cause the teeth 432 thereof to cooperate with the teeth 425 and 436 of the relatively fixed inner and outer spline rings 424 and 434 to grip the-external spline teeth 484 of a workpiece 485 vise-fashion and maintain the grip without danger of accidental loosening. Likewise, rotation of the cam rod 456 in the opposite direction will release the grip and, when such rotation is completed, which occurs when the fiat surface 414 engages the side 443 of the slot 542, the teeth 432 of the middle spline ring 433 will be brought into register with the teeth 428 and 435 of the inner and outer spline rings 424 and 434, so that the workpiece may be readily slipped into and out of mesh with the spline chuck 423.

The workpiece 483 may be of any form. If it is hollow, as shown, and the work to be performed involves precision machining which must be concentric to the pitch circles of the workpiece spline teeth 484, provision is made for properly mounting the chuck 426 for that purpose. To this end, the backing plate 422 is made hollow with an axial frusto-conical opening 438 which will accommodate the usual 60 center 49!] of a lathe or other machine tool, the frusto" conical opening being co-axial with the various spline teeth.

In the constructions above described, the cam rod is directly operated against the adjustable spline ring and the cam is eccentrically located. Figs. 20 to 23 show a form of spline chuck employing a similar principle but in which the camming operation is somewhat indirect and the chuck is approximately in static and dynamic balance to render it particularly (though not exclusively) useful where the workpiece 498, such as an impeller, is to be tested and treated to have static and dynamic balance. This arbor is indicated generally at 500 and has reduced ends 50! W and. 502. The arbor 505 has an intermediate en larged cylindrical shaft portion 554 having integral inner and outer external spaced spline rings 506 and 558 having identical registered spline teeth th and 5:2, respectively, the space 5H! between said rings being in a form of an annular groove in which is disposed an adjustable middle spline ring 23 i ii having external teeth 5|! identical with and adapted to be rotated into and out of register with and to cooperate with the aforesaid teeth in chucking the internal spline teeth 5; of the workpiece 588. The middle spline ring 5l6 is formed of two halves 5l9 and 525 held together preferably by socket head screws 522. The reduced part 525 the shaft pcrticn 5H4 defining the bottom of the annular groove 5M has a diametrical slot 525 in which is non-rotatable but longitudinally slidable a cam element 528 whose ends 53d and 532 project radially outward into inner diametrically opposite longitudinal slots 53d and 555, respectively, formed in the middle spline ring One side 53%, 565 of each spline ring slot 53d, is inclined to cooperate camwise with an inclined face 525, 5 34 of each projecting end portion 535, 532 of said cam element 528, and, when the spline teeth 5!! of the middle spline ring 5H5 are in register with the spline teeth 5E5, 5|2 of the other two rings 5%, 508, the arrangement of the parts is as shown in Fig. 21.

An axial bore see is formed in the arbor end 502 and a portion of the shaft section 554 and intersects the diametrical slot 525, and contains a cylindrical cam rod 552 having an annular external groove etc in which are disposed opposite keeper pins E driven in holes 58 in theshaft section, one of said pins being sufiicient to conflne said rod to rotary motion and the other pin being provided for static balance.

The rod 52 has an end cam portion projects into a transverse slot 554 in the cam eleemnt or pin 5'33, said slot having parallel sides 565 and 568 which have simultaneous engagement with opposite curved cam surfaces 515 and 512 of the cam portion The cam portion 552 is symmetrically cut away on opposite sides to provide in diametrically opposite quadrants the curved cam surfaces 5% and 5H, each of gradually reduced radius from the normal cylindrical surface .of an intermediate quadrant, shown at 514, and further cut away toprovide, at theminimum radial ends of said cam surfaces, tangential fiat surfaces 5% and bill 90 to each other, the diametrical distance between said cam surfaces,

measured through the axis 555 of the cam rod 552, being uniform for allportions of said cam surfaces.

The outerend of the cam rod 552 has awrench socket 582 to receive a wrench for rotating the cam rod from its neutral position, shown in Figs. 20 and 21, when the teeth 5%? of the middle spline ring 5l5 are in register with the teeth 510, 512 of the relatively fixed spline rings 555, 508, so that the workpiece 458 may be readily slippedto the position shown in Fig. 20, in a clockwise direction, as indicated by the arrows 584, to shift the middle spline ring in the direction indicated by the arrow 585 to cause each internal spline tooth 5th of the workpiece tobe gripped viselike intermediately by the iddle spline ring teeth on one side and at the end portions by the fixed spline teeth on the other side, as may be gathered from Figs. 4 and 22. By virtue of the engagement of portions of progressively increasing radius of the curved cam surface 5% with the 552 which side 566 of the slot 564, the cam pin 528 is forced in the direction of the arrow 586 (Fig. 21) caus ing the inclined cam surface 542 of the end 530 of the pin to act on the adjacent inclined cam surface 538 of the middle spline ring slot 535 so as to shift the middle spline'ring in the direction of the arrow 585, said slot being wider than said end of the pin to provide'clearance for such shift of the middle spline ring. As portions of 'progressively increasing radius of the curved cam surface 510 engage one side 566 of the slot 564 in the middle spline ring shifting operation, portions of progressively reduced radius on the other curved cam surface 512 confront the otherside 558 of said slot to permit the cam pin 528 to move in the diametrical hole 525, the locking cam surface 515, when the workpiece 458 is clamped on the arbor chuck 580, being securely wedged and in effect locked against the adjacent slot side 566 so that it cannot accidentally be loosened. The arrangement of the parts at this point is shown in Fig. 22.

With the workpiece 4.98 clamped to the chuck 500, the assembly may be supported at its end spindles 55!, 592 on knife edges (not shown) and the workpiece tested and treated to statically balance the same, and then the assembly is placed in a dynetic balancing machine to test and corroot the workpiece for dynamic balance.

When the workpiece A98 is to be released, the operator inserts a wrench into the cam rod socket 552 and rotates the cam rod 552 in a counter-clockwise direction, as indicated by the arrow 588 in Fig. 22, whereupon the two curved cam surfaces 510 and 512 reverse their previous roles in cooperation with the respective sides 568 and 55B of the cam pin slot 564, the pin5i28 being caused to move in the direction of the arrow 590 so that the inclined cam surface 544 of the other end 532 of the cam pin 528 engages the adjacent inclined cam side 540 of the other slotl536 in the middle spline ring 5 l 6 to turn the latter counterclockwise as shown by the arrow 592 (Fig.22) so that, when the flat tangential surface 5161 reaches the position shown in Fig. 21, the middle spline ring teeth 51'! are again in register with the fixed spline teeth 5E5 and 5E2, whereupon the workpiece is free to be slid off the chuck 5B0.

Figs. 24 to 29 show generally at 505 a still further form of chuck according to my invention, wherein a cam rod 652 similar to certain of the cam rods previously described operates on a plurality of other parts to bring about the desired shift of the middle spline ring. .In this construction there is provided a body 603 having a backing plate 5% and a, shaft extension or hub 60% comprising spaced inner and outer fixed spline rings 5% and 6m having external teeth EH2 and th s and an intervening annular groove tlB in which is rotatably received an adjustable middle spline ring 5&5 having teeth 520 and "formed of two halves E52! held together as by socket head screws 522, all of said teeth being identical. The hub 55 5 has abore 524 which extends through the outer spline ring 5H) and into 7 the intermediate reduced portion 626 and merges into a tapered bore iizileirtendin'g throughthe' remainder of the hub and partlyinto the backingplate 504, said tapered bore merging with a substantially enlarged cylindrical counter-bore 535 in the backing plate and providing a shoulder 632.

" A plunger shown generally at 535 has a stem 63'! with a cylindrical reduced free end portion 638 which fits into the cylindrical bore .824, an

ll adjacent tapered portion 646 which fits into the tapered opening 626 but whose taper is of smaller angularity, and a cylindrical head 662 which fits in the counter-bore 636 and is capable, as will appear, of combinedlongitudinal and rotary sliding J movement therein. "A' helical slot 644 is for-medin the outer periphery 646 of the plunger head 642, and a pin 646 threaded radially in the backing plate 664 projects inwardly of the periphery of the counter-bore 636 into the helical slot.

-The backing plate 666 hasdiametrically alined keyways 656 and bores 658 and 666 and the machine tool may have a chuck 662 therefor arranged with its axis vertical and corresponding keyways 663 and bores 666 and 666. Keys 661 are fitted in the respective keyways 656 and 666 to aline the bores 656 and 666 with the bores 666 and 666. The plunger head 662 has a diametrical elongated slot 668 held in line with the bores 656 and 666 by the cam rod 662 which extends therethrough and through all of said bores and is journaled in bushings 616 and has its ends 612 and 614 extending beyond the periphery of the machine tool chuck 662, a .washer 615 and a handle 616 being disposed about one end 612 and secured at 618 thereat, and a, collar 686 being se cured at 686 to the end 616, whereby the cam rod is confined to rotary movement. The cam rod 662 has an intermediate cam portion 666 which passes through the plunger head slot 668. The cam portion 690 is cut symmetrically on opposite'sides to provide, throughout diametrically opposite quadrants thereof, curved cam surfaces 662 and 666 of progressively reduced radius from the. normal cylindrical surface 696 of one of the intervening. quadrants, and, at the minimum radial portions of said curved cam surfaces, tangential surfaces 104 and 166 90 apart. The distance between the cam surfaces 662 and 694 through the axis 161 of the cam rod 662 is uniform for all portions of the respective cam surfaces, and said cam surfaces have simultaneous sliding engagement with the parallel sides 166 and N6 of the slot 668.

The plunger stem end portion 638 has a diametrical. axially elongated slot 156 and the reduced hub portion 626 has diametrically opposite radial circumferentially elongated slots 1l-8 which partially register with the plunger slot H6. The middle spline ring 6E6 has diametrically opposite holes 126 in which is driven a preferably cylindrical pin 122 which passes through and has sliding engagement with the sides of the hub slots H8 and the plunger slot H6, as shown in Figs. 26 and 29. The ends 124 and 126 of each hub slot 118 and the ends 121 and 123 of the plunger slot 1l6 are spaced apart a distance exceeding the diameter of the pin 122.

With the parts arranged as shown, the flat surface 166 of the cam rod 662 is engaged with the 'side H6 of the plunger slot 668, so that counterclockwise rotation of the cam rod, looking at Fig. 27, cannot occur, the teeth 620 of the middle spline ring 6|8 are in register with the teeth 6l2 and 6 [4 of the fixed spline rings 666 and GIG, and the handle 616 extends upward so that the weight 136, disposed at the outer end of the handle, is uppermost. Now the internal spline teeth 134 of the workpiece 136 are slipped into splined relation with all of the arbor spline teeth. The knob 136, extending from the weight 136, is now grasped and pulled to the right (Figs. 24 and 25) .sufiiciently to enable the weight to swing by the cam rod 662 will rotate clockwise. Such rotation' of the cam rod 662effects axial movement of the plunger 636 in the direction of the arrow 146 by virtue of the cam action of the cam surface 694 against the side N6 of the plunger head slot 668, the opposite cam surface 692 being radially relieved as aforesaid to permit the other side 16B of the slot to shift correspondingly, and, due to the co-action of the inner end of the stationary pin 646 with the sides of the helical slot 644, the plunger will have slight rotary movement at the same time in the direction of the arrow 1 i2 (Fig. 26). Accordin l the pin 122, and with it the middle spline ring 6|8, is rotated to cause the middle spline ring teeth 626 to move out of register with the fixed spline ring teeth (H2 and 6M and cooperate with said fixed teeth in securely clamping the internal teeth 13 of the workpiece 136 vise-fashion, the handle 616 having by that time turned through a substantial angle as indicated by the dash-dot lines in Fig. 25. It :will be noted that the length of the plunger stem slot 116 and the hub slots 1E6 substantiall exceed the diameter of the pin 122 to provide for lost motion, due to the combined axial and rotary movement of the plunger 636, and thatthe cam surface 694 has a locked wedge engagement with the side N0 of the slot 668, said engagement being releasable only upon manual rotation of the handle 616 counter-clockwiseiFig. 25). Upon such counter-clockwise movement of the handle 616, the pressure of the middle spline ring teeth against the workpiece spline teeth is relaxed, enabling the workpiece 136 to be readily slipped off, and when such movement is completed, the flat surface 166 of the cam rod 662 is again in contact with the side 156 of the plunger slot 668, and all of the chuck spline teeth are again in register, enabling another internally splined workpiece to be slipped on the chuck.

The form of my invention shown in Figs, 30, 31 and 32 is also of the indirect external manual type but, although somewhat similar to the form shown in Figs. 24 to 29, is adapted for a different kind of installation and accordingly in certain respects differs therefrom. As shown in Fig. 36, I provide a spline-chuck arbor generally indicated at 156 and comprising a shaft body 152 having spaced fixed inner and outer external spline rings 154 and 156 having teeth 158 and 166, respectively, and an intervening adjustable spline ring 162 having teeth 16 i identical with the aforesaid teeth and madein'two parts 166 and 16B connected together as by socket head screws 116. The shaft 152 is hollow and has a cylindrical end bore 112 extending through the fixed spline rings and adjacent reduced shaft portion 116 and merging with a co-axial tapered bore 116 terminating at its larger end at the shoulder 118 of a cylindrical counter-bore 166 at the other end 162 of the shaft. A plunger 184 has a stem 186 including a cylindrical end portion 169 slidably fitted in th bore 112, a tapered portion 166 of smaller angularity than and disposed in the tapered bore 116 and adapted to project into the counter-bore 166, and a cylindrical head 162 slidably engaging the peripheral wall 196 of the counter-bore-180. A keeper plate 196 is secured at 198 to the adjacent end 182 of the shaft 152 and serves as a stop engageable with the free end 866 of the plunger head 192 to limit movement of .said head in the direction in which said head is urged by springs 862 seated in preferably three equally spaced holes 804 formed in the head, said 13 springs being under compression between said head and the shoulder 118.

The end 8051 of the plunger head 92 has a center ball socket 835 in which is received a ball 8M forming one end of a ram 808, the other end 8H1 of which has a diametrical slot 8I2 in which a cam M4 is slidably engageable, said cam being in the form of a collar keyed at 3H5 or otherwise suitably secured to a shaft 8H3 journaled as at 82!] and carrying a handle 822 secured to the shaft as at 824. A quadrant of the cam M4 is in the form of a curved cam surface 826 of progressively reduced radius from one end 828 to the other end 839, the cam having flat surfaces 832 and 834 tangent to said ends.

The plunger head [92 has a helical slot 840 and the adjacent end portion 182 of the shaft 152 has a radial bore in which a. pin or dowel 8 32 is driven, said pin projecting into and cooperating with the sides of the heiical slot as noted in the form just described and as will appear. The cylindrical end 188 of the plunger stem 186 has an axially elongated diametrical slot 844 and the reduced portion il of the shaft 152 has diametrically opposite radial circumferentially elongated slots 8 36 through all of which extends a preferably cylindrical pin 84! driven in diametrically opposite radial holes 848 in the middle spline ring Hi2, said pin having sliding engagement with the walls of said slots.

The spline chuck 255i is adapted to be keyed as at 850 to a machine tool chuck plate 852 adapted to be keyed as at 854 and bolted as at 856 to a machine tool chuck head i358 bored as at 850 to provide a bearing and guide for the body portion 852 of the ram 808, rotation of which is prevented by the cam 81%.

When the several parts are arranged as shown, the middle spline ring teeth its are in register with the fixed spline ring teeth and "E59, so that the spline chuck its is prepared to receive the internal spline teeth 866 of a workpiece 868. To clamp the workpiece on the spline chuck I50, the operator rotates the handle 822 in the direction indicated by the arrow all! (Fig. thereby rotating the cam shaft 8&3 and with it the cam BM in the direction of the arrow 612 (Fig. 32) and forcing portions of the curved cam surface 826 of progressively increasing radius against the base 814 of the ram slot 8|2 to thereby impart axial. movement to the ram 808, whose ball 804 thus forces the plunger "i3 3 in the direction of the arrow Bit, against, the resistance of the springs 892. By virtue of the coaction of the side EH8 of the helical slot 346 with the relatively stationary dowel. M2, the plunger 384 will be subjected to a rotary motion also, with the result that the pin M6. and consequently the middle spline ring 5152 will rotate, causing the middle spline ring teeth Hi l to move out of register with the fixed spline teeth T58 and Hill and thus clamping the internal spline teeth $66 of the workpiece 36B vise-fashion between the middle spline ring teeth intermediately at one side and the fixed spline ring teeth at the ends of the other side of each workpiec tooth. When the clamping is efiected, the curved cam surface 828 is in tight and eiiectively locked wedging engagement with the bottom surface 814 of the ram slot 8i2, so thataccidental disturbance of the cam 854 cannot occur.

To release the workpiece 868, the operator rotates the handle 822 and hence the cam 814 in the opposite direction, thereby releasing the wedging engagement and permitting the springs 802 to reverse the translatory and rotary motion of the plunger 184 until the end 800 of the plunger head 192 abuts the keeper plate 196, and. when this abutment takes place, the middle spline ring teeth 164 are again in register with the fixed spline ring teeth I58 and "Hill, enabling the workpiece to be removed.

In the construction just described, the plunger is moved in one direction by a manually actuated ram and is spring-returned. In some installations provision is made for operating the ram hydraulically or pneumatically, so that the ram moves the plunger in both direction and hence no spring-return is used. Such an arrangement is shown in Figs. 33 to 38. Parts of the mecha'- nism shown in. Figs. 33 to 38 which are identical with those just above described are like-humbered. The plunger 9% differs from the plunger 184 in that, instead of having a ball socket, it has at the free end 932 of its head can a tapped axial opening Stein which the end 9D8'0f1a ram 9H] is threaded. The ram 910 is a piston rod whose other end is connected to a piston 912 which moves in a hydraulic or pneumatic cylinder 914, the admission and exhaust of the hydraulic or pneumatic medium being controlled in any suitabl manner by means not shown. The operation of this form of my invention is like that of the form shown in Figs. 30 to 33, except that the return movement of the Plunger 900, which is to the right, looking atFig. 33,, is effected positively by fluid pressure appliedlto the end 9P6 of the cylinder 9M. The piston EH2 is capable of rotation as well as translation inthe cylinder, so that the piston will turn not only pursuant to the slight rotary motion of the plunger 900. in its forward and return movements, but also as a unit with the arbor when the work.- piece 868. is subjected to machining operations.

Various modifications coming within the spirit of my invention may suggest themselves to those skilled. in the art, and hence I do not wish to be limited to the specific forms shown or uses mentioned, except to the extent indicated in the appended claims, which are to be interpreted as broadly as the state of the art will permit.

I claim:

1. A spline chuck comprising a body including relatively fixed axially spaced spline teeth, means rotatable relative to and including a spline tooth disposed between said spaced spline teeth, a rotatable element carried by said body, cam means actuatable by said element and including a pair of cam surfaces, said rotatable means having a pair of faces adjacent and co-operative with the respective cam surfaces, one cam surface being operative against the face adjacent thereto to rotate said'rotatable means in a direction to bring said tooth out'of register with said fixed teeth to clamp a spline tooth of a workpiece between said fixed-teeth on one side and said tooth of said rotatable means on the other side, when said element is rotated in one direction, the other cam surface being operative against the face adjacent thereto to rotate said means in the opposite di rection to unclainp the spline toothof the workpiece, when said element is rotated in. the other direction.

2. Achuck comprising a body includingrelatively fixed spaced members each having atooth, means. movable relative to and including a tooth between said spaced members, a movableactuating element. carried by. said body, cam means actuatablebysaid element and includinga pair of cam surfaces, said movable means having a 15 'pair of faces adjacent and co-operative with the respective cam surfaces, one cam surface being operative against the face adjacent thereto to move said movable means in a direction-to clamp a tooth of a workpiece between said spaced teeth on one side and said tooth of said movable means on the other side, when said element is moved in one direction, the other cam surface being operative against the face adjacent thereto to move said movable means in the opposite direction to unclamp the tooth of the workpiece, when said element is moved in the other direction.

3. A chuck comprising a body including relatively fixed spaced members each having a tooth, means movable relative to and including a tooth between said spaced members, a movable actuatin element carried by said body, cam means actuatable by said element and including a pair of cam surfaces, said movable means having a pair'of faces adjacent and co-operative with the respective cam surfaces, one cam surface being operative against the face adjacent thereto to move said movable means in a direction to clamp a tooth of a workpiece between said spaced teeth on one side and said tooth of said movable means on the other side, when said element is moved in one direction, the other cam surface being operative against the face adjacent thereto to move said movable means in the opposite direction to unclamp the tooth of the workpiece, when said element is moved in the other direction, both of said cam surfaces being at all times engaged. with the respective faces.

4. A spline chuck for a workpiece which when finished, is to be in static balance, said chuck comprising a cylindrical body having fixed spaced coaxial spline rings whose teeth are identical and in register and an intervening body portion of reduced thickness, providing an annular space, a relatively rotatable coaxial splin ring fitted in said space and having teeth identical with and adapted to be rotated into and out of register with the aforesaid teeth, said body portion having a diametrical hole therethrough, a cam pin diametrically slidable in said hole, said rotatable spline ring having diametrically opposit openings into which the ends of said pin project, said openings at one side of said pin being tapered and the adjacent sides of the ends of said pin being engageable cam-wise selectively with the respective tapered sides of said openings, pursuant to movement of said pin selectively in one direction or the other in said hole, to cam said rotatable ring selectively in one direction of rotation or the other, and means coaxial with said rings and operative to shift said pin selectively in one or the other direction in said hole, whereby said rotatable spline ring may be rotated in a, direction to cause its teeth to move out of register with the fixed spline teeth and clamp the spline teeth of 1 a workpiece, in which event the weight of said pin at opposite sides of the axis of said rings is substantially the same, or in the opposite direction to reregister the several spline teeth of said chuck to enable the workpiece to be removed.

5. Aspline chuck for a workpiece which, when finished, is to be in static balance, said chuck comprising a cylindrical body having fixed spaced co-axial spline rings whose teeth are identical and in register and an intervening body portion of reduced thickness, providing an annular space, a relatively rotatable coaxial spline ring fitted in said space and having teeth identical with and adapted to be rotated into and out of register with 1d the aforesaid teeth, said body portion having a diametrical hole therethrough, a cam pin diametrically slidable in 'said hole, said rotatable spline ring having diametrically opposite openings into which the ends of said pin project, said openings at one side of said pin being tapered and the adjacent sides of the ends of said pin being engageable cam-wise selectively. with the respective tapered sides of said openings, pursuant to movement of said pin selectively in one direction or the other in said hole, to earn said rotatable ring selectively in one direction of rotation or the other, and means coaxial with said rings and operative to shift said pin selectively in one or the other direction in said hole, whereby said rotatable spline ring may be rotated in direction to cause its teeth to move out of register with the fixed spline teeth and'clamp the spline teeth of a workpiece, in which event the weight of said pin at opposite sides of the axis of said rings is substantially the same, or in the opposite direction to reregister the several spline teeth of said chuck to enable the workpiece to be removed, said pin having a center transverse slot, said body having an axial cylindrical bore, said means com prising a cylindrical rod movably fitted in said bore, said rod having cam surfaces co-operating with the sides of said pin slot to shift said pin diametrically selectively in one direction or the other.

6. A spline chuckfor a workpiece which, when finished, is to be in static balance, said chuck comprising a cylindrical body having fixed spaced co-axial spline rings whose teeth are identical and in register and an intervening body portion of reduced thickness, providing an annular space, a relatively rotatable coaxial spline ring fitted in said space and having teeth identical with and adapted to be rotated into and out of register with the aforesaid teeth, said body portion having a diametrical hole therethrough, a cam pin diametrically slidable in said hole, said rotatable spline ring having diametrically opposite openings into which the ends of said pin project, said openings at one side of said pin being tapered and the adjacent sides of the ends of said pin being engageable cam-wise selectively with the respective tapered sides of said openings, pursuant to movement of said pin selectively in one direction or the other in said hole, to cam said rotatable ring selectively in one direction of rotation or the other, and means coaxial with said rings and operative to shift said pin selectively in one or the other direction in said hole, whereby said rotatable spline ring may be rotated in a direction to cause its teeth to move out of register with the fixed spline teeth and clamp the spline teeth of a workpiece, in which event the weight of said pin at opposite sides of the axis of said rings is substantially the same, or in the opposite direction to reregister the several spline teeth of said chuck to enable the workpiece to be removed, said pin having a center transverse slot, said body having an axial cylindrical bore, said means comprising a rotary cylindrical rod fitted in said bore, said rod having a cam cooperating with the sides of said pin slot to shift said pin diametrically selectively in one direction or the other, said cam comprising diametrically opposite curved surfaces of progressively increased radius, the diametrical distance between said curved surfaces, through the axis of said rod, being uniform for all portions of said curved surfaces and being substantially equal to the width of said pin slot, whereby, as portions of progressively increased diameter of either curved surface engage the adjacent side of said pin slot, said pin will be correspondingly shifted, the increment in radius of said curved surfaces being so slight that, when the workpiece is tightly clamped, one of said curved surfaces will be in tight wedging engagement with the co-operating side of said slot.

7. A spline chuck for a workpiece which, when finished, is to be a static balance, said chuck comprising a cylindrical body having fixed spaced co-axial spline rings whose teeth are identical and in register and an intervening body portion of reduced thickness, providing an annular space, a relatively rotatable coaxial spline ring fitted in said space and having teeth identical with and adapted to be rotated into and out of register with the aforesaid teeth, said body portion having a diametrical hole therethrough, a cam pin diametrically slidable in said hole, said rotatable spline ring having diametrically opposite openings into which the ends of said pin project, said openings at one side of said pin being tapered and the adjacent sides of the ends of said pin being engageable cam-wise selectively with the respective tapered sides of said openings, pursuant to movement of said pin selectively in one direction or the other in said hole, to cam said rotatable ring selectively in one direction of rotation or the other, and means coaxial with said rings and operative to shift said pin selectively in one or the other direction in said hole, whereby said rotatable spline ring may be rotated in a direction to cause its teeth to move out of register with the fixed spline teeth and clamp the spline teeth of a workpiece, in which event the weight of said pin at opposite sides of the axis of said rings is substantially the same, or in the opposite direction to reregister the several spline teeth of said chuck to enable the workpiece to be removed, said pin having a center transverse slot, said body having an axial cylindrical bore, said means comprising a rotary cylindrical rod fitted in said bore, said rod having a cam cooperating with the sides of said pin slot to shift said pin diametrically selectively in one direction or the other, said cam comprising diametrically pposite curved surfaces of progressively increased radius, the diametrical distance between said curved surfaces, through the axis of said rod, being uniform for all portions of said curved surfaces and being substantially equal to the width of said pin slot, whereby as portions of progressively increased diameter of either curved surface engage the adjacent side of said pin slot, said pin will be correspondingly shifted, the increment in radius of said curved surfaces being so slight that, when the workpiece is tightly clamped, one of said curved surfaces will be in tight wedging engagement with the co-operating side of said slot, said cam having a flat surface tangent to the portion of minimum radius of each curved surface and selectively engageable with the respective sides of said pin slot to limit the rotation of said rod in each direction, one of said flat surfaces engaging one of said pin slot sides when all of the spline teeth of said chuck are in register.

8. A spline chuck comprising a body, axially spaced. spline rings fixed to said body and having registering teeth, a relatively rotatable spline ring in the space between and on the same axis as said fixed spline rings and adapted to be rotated to bring its teeth into and out of register with said fixed teeth, a member coaxial withsaid 18 rings, means for imparting axial movement to said member in each direction, means providing an axial lost motion connection between said member and said rotatable spline ring, and means operative upon axial movement of said member to rotate said member, whereby, upon operation of the first mentioned means to move said member in one direction, said rotatable spline ring will rotate to cause its teeth to move out of register with said fixed teeth and thereby cause each spline tooth of a workpiece positioned on said fixed teeth to be locked vise-fashion between a tooth of said rotatable spline ring on one side and fixed spline teeth on the other side.

9. A spline chuck comprising a body including relatively fixed axially spaced sets of registering spline teeth, a device rotatable relative to said body and having a slot and including a set of spline teeth disposed between the aforesaid sets, a rotatable cam carried by said body and having cam surfaces in sliding engagement with the sides of said slot, each of said cam surfaces being of progressively increased radius, whereby, upon rotation of said cam in a direction to cause portions of progressively increased radius of one of said cam surfaces to engage the co-operating side of said slot, said device will be rotatably shifted to bring its set of spline teeth out of register with the spline teeth of said fixed sets, to clamp each spline tooth of a workpiece between a tooth of said rotatable set on one side and a tooth of each of said fixed sets on the other, the increment in radius of said one cam surface being so slight that when the workpiece spline teeth are tightly clamped between the several sets of teeth, said one cam surface will be in tight wedging engagement with said co-operating side of said slot, means limiting such rotation of said cam, and whereby, upon rotation of said cam in the opposite direction, portions of progressively increased radius of the other cam surface will similarly engage the other side of said slot and thereby rotate said device until its spline teeth are in register with said fixed teeth, and means stopping such opposite rotation of said cam when the teeth of all of said sets are in register.

10. A spline chuck comprising a body including relatively fixed axially spaced sets of registering spline teeth, a device rotatable relative to said body and having a slot and including a set of spline teeth disposed between the aforesaid sets, a rotatable cam carried by said body and having cam surfaces in sliding engagement with the sides of said slot, each of said cam surfaces being of progressively increased radius, whereby, upon rotation of said cam in a direction to cause portions of progressively increased radius of one of said cam surfaces to engage the co-operating side of said slot, said device will be rotatably shifted to bring its spline teeth out of register with said fixed sets, to clamp each spline tooth of a workpiece between a tooth of said rotatable set on one side and a tooth of each of said fixed sets on the other, the increment in radius of said one cam surface being so slight that when the workpiece spline teeth are tightly clamped between the several sets of teeth said one cam surface will be in tight wedging engagement with said co-operating side of said slot, and whereby, upon rotation of said cam in the opposite direction, portions of progressively increased radius of. the other cam surface will similarly engage the other side of said slot and thereby rotate said device until its spline teeth are in register with said fixed teeth.

11. A spline chuck comprising a body including relatively fixed axially spaced sets of registering spline teeth, a device'rotatable relative to said a rotatable cam carried by said body and having 'cam surfaces in sliding engagement with the sides j and a tooth of each of said fixed sets on the other, "the increment in radius of said one cam surface being so slight that when the workpiece spline teeth are tightly clamped between the several sets of .teeth; said one cam surface will be in tight wedging engagement with said co-operating side of said slot, and whereby, upon rotation of said cam in the opposite direction, portions of progress'ively increased radius of the other cam surface will similarly engage the other side of said slot and thereby rotate said device until its spline teeth are in register with said fixed teeth, and means stopping such opposite rotation of said cam when all of said spline ring teeth are in register. I I

12'. A spline chuck comprising a body having spaced fixed sets of spline teeth, a relatively rotatable member including a ring disposed between said sets and formed with a set of spline teeth adapted to be moved into and out of register with the aforesaid sets of teeth, said body having a'recessed portion affording a bearing for said ring, a cam shaft carried by said body and having curved cam surfaces of identically and progressively increased radius, said cam shaft having a straight portion tangent to the end of each cam surface of least radius, said ring having circumferentially spaced straight portions, one of said cam shaft portions being engaged with one of said straight ring portions when all of said teeth are in register, whereby, when said cam shaft is rotated in a direction to cause portions of progressively increasing radius of the cam surface adjacent one of said straight cam shaft portions to engage said one straight ring portion said member will be rotated to bring its spline teeth out of register with said fixed teeth to thereby clamp the spline teeth of a workpiece, the increment in radius of said cam surfaces being so slight that the last mentioned cam surface, as the clamping pressure is increased, is securely wedged against said one straight ring portion to preclude accidental loosening of said cam shaft, said rotation of said cam shaft being stopped by virtue of the engagement of the other straight cam shaft portion with the other straight ring portion, and whereby, upon return rotation of said cam shaft, portions of progressively increasing radius of said other cam surface will earn against the other straight ring portion to cause reverse rotation of said member until all of said teeth are again in register.

13. A spline chuck comprising a body having spaced fixed sets of spline teeth, a relatively rotatable member including a set of spline teeth between and adapted to be moved into and out of register with said fixed sets of teeth, said body having a recessed portion affording a bearing for said member having a slot in which said cam portion extends, said slot extending parallelto the teeth of said member, whereby, when said cam shaft is rotated in a direction to cause portions of progressively increasing radius of one cam surface to engage a side of said slot, said member will be rotated to bring its spline teeth out of register with said fixed teeth, to thereby clamp the spline teeth of a workpiece, the increment in radius of said cam surfaces being so slight that said one cam surface, as the clamping pressure is increased, is securely wedged against said side to preclude accidental loosening of said cam shaft, and whereby, upon return rotation of said cam shaft, portions of progressively increasing radius of said other cam surface will cam against the other side of said slot to cause reverse rotation of said member until all of said teeth are again in register.

14. A spline chuck comprising a body having axially spaced fixed spline rings, a relatively rotatable spline ring member in the space between and on the same axis as said fixed spline rings, a member co-axial with said rings, means for shifting the second member longitudinally of said axis selectively in each direction and co-operating means on said body and second member for imparting rotary motion to said second member upon such longitudinal shift thereof, one of said members having spaced axially elongated portions, the other member having pin means slidably engageable with said portions, whereby, upon shift of said second member in a predetermined direction, said rotatable spline ring member will rotate to cause each spline tooth of a workpiece meshed with said fixed teeth to be locked Visefashion between a tooth of said rotatable spline ring member on one side and teeth of said fixed spline rings on the other side.

15. A spline chuck comprising a body having axially spaced fixed spline rings, a relatively rotatable spline ring member in'the' space between direction, said cam surface will shift said second member and consequently said rotatable spline ring member will rotate to cause each spline tooth of a workpiece meshed with said fixed teeth to be clamped vise-fashion between a tooth of said rotatable spline ring member on one side and a tooth of each of said fixed spline rings on the otherside, said cam surface being of gradually increased radius so as to be tightly wedged against said face when the workpiece is clamped as aforesaid.

16. A spline chuck comprising a body having axially spaced fixed spline rings, a relatively rotatable spline ring member in the space between;

and on the same axis as said fixed spline rings, a member co-axial with said rings, means for shifting the second member longitudinally of said axis selectively in each direction and co-operating means on said body and second member for imparting rotary motion. to said second member upon such longitudinal shift thereof, one of said members having spaced axially elongated portions, the other member having pin means slid- 

